Field of the Invention
The present invention relates to a shock absorber having a shock absorber tube and having an external module tube which is arranged retentively on the outside of the shock absorber tube by means of a flange, wherein the flange has one or more fluid ducts which fluidically couple the module tube to the shock absorber tube.
Description of Related Art
DE 11 2007 002 377 T5 has disclosed, for example, a shock absorber with a shock absorber tube, and an external module tube is provided in which a further valve arrangement is accommodated. In this case, the module tube extends perpendicular to the shock absorber tube, and the flange for connecting the module tube to the shock absorber tube is formed by the module tube itself.
DE 11 2008 001 980 T5 has disclosed a shock absorber with a shock absorber tube and an external module tube in which a valve body arrangement is accommodated. Between the shock absorber tube and the module tube there are situated transfer rings which form a flange between the two tubes and by means of which the module tube is attached retentively to the shock absorber tube. Fluid ducts are formed through the transfer rings in order to connect the valve body arrangement in the external module tube to the shock absorber tube. In this case, the maximum possible distance between the module tube and the shock absorber tube is structurally limited by the design of the transfer rings.
The connection between the module tube and the shock absorber tube must perform a mechanical retention function in addition to the fluidic connection function. This demands a high level of mechanical strength of the module tube on the shock absorber tube, and if the distance between the module tube and the shock absorber tube has to be increased, for example for structural reasons, it is no longer possible for the flange connection between the module tube and the shock absorber tube to be formed by transfer rings, as these can no longer withstand adequate mechanical load.
It is duly possible for a flange composed of a metallic material to be provided, which makes it possible to realize a high level of strength between the module tube and the shock absorber tube, in particular if the tubes are welded to the flange, but a flange composed for example of a metallic solid material may easily exhibit a high weight. In particular in situations where shock absorber tubes are used as unsprung masses on a vehicle, it is important to realize a low weight of the shock absorber. A flange composed of a plastics material would duly be lighter but would not exhibit the required strength, and the module tube would not be attached to the shock absorber tube with adequate mechanical strength.
If, for example, a flange composed of a metallic solid material is provided, there is also the problem of sealing off the fluid ducts with respect to the tube bodies. The fluid ducts must pass through the flange and be connected to openings formed in the shock absorber tube and in the module tube. If the connection between the flange and the tubes is formed by a welded connection, this makes it difficult to realize sealing between the fluid ducts in the flange and the outer sides of the tubes.